Motorcycle frame



FIG. 1 is a front elevational view;

FIG. 2 is a front elevational view, the rear elevational view being a mirror image thereof;

FIG. 3 is a top plan view;

FIG. 4 is a bottom plan view;

FIG. 5 is a right side elevational view; and,

FIG. 6 is a left side elevational view of my motorcycle frame.

The dotted lines showing a motorcycle in FIG. 1 are environmental only and form no part of the claimed design. 

The ornamental design for a motorcycle frame, substantially as shown and described. 